Chrome Native-Client

Native Client is a sandbox for running compiled C and C++ code in the browser efficiently and securely, independent of the user’s operating system. Portable Native Client extends that technology with architecture independence, letting developers compile their code once to run in any website and on any architecture.
In short, Native Client brings the performance and low-level control of native code to modern web browsers, without sacrificing the security and portability of the web. Watch the video below for an overview of Native Client, including its goals, how it works, and how Portable Native Client lets developers run native compiled code on the web.